Self-effacing (6)
I believe the answer is:
modest
'self-effacing' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for modest that I've seen before include "Inexpensive" , "Unassuming; limited" , "Not vain, rather shy" , "Avoiding indecency; unassuming" , "Bashful" .)